Frame for supporting a dome shaped building



Aug. 1, 1967 A. E. JOHNSTON 3,333,375

FRAME FOR SUPPORTING A DOME SHAPED BUILDING Filed OOLv 8, 1964 INVENTOR Aflar? faaswg ATTORNEY United States Patent O 3,333,375 FRAME FOR SUPPORTING A DOME SHAPED BUILDING Arthur E. Johnston. Winston-Salem, N.C., assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Filied Oct. 8, 1964, Ser. No. 402,533 10 Claims. (Cl. 52-81) ABSTRACT F THE DISCLOSURE A frame for a spherical-shaped building having a plurality of hollow structural elements arranged in a three dimensional array of intersecting circles of a sphere to form a substantially spherical pattern. A plurality of hollow joints interconnect the ends of adjacent structural elements in each circle of the sphere. A plurality of tensioned laments are utilized for stabilizing and strengthening the frame. One group of filaments passes through each of the hollow structural elements and hol- =low joints of one group of circles of the sphere. Another group of filaments is connected externally to alternating joints in another group of circles of the sphere.

'Ihis invention relates to a frame for a building. More particularly, this invention relates to a frame for a spherical-shaped -building having a plurality of structural elements arranged in a substantially semi-spherical pattern ot arcs of circles of such pattern and having facilities for maximizing the strength thereof.

In the construction of buildings and tent-like structures for radar antennas, space stations, and objects requiring weather protection, structural elements have been arranged in generally spherical-shaped patterns to produce a favorable ratio of structural strength to structural weight. A perplexing problem has been the increasing of this ratio to enhance the capacity of the building to withstand high stresses due to weather conditions and the carrying of heavy loads. Also, it is desirable to increase this ratio to facilitate transportation and erection of the building.

Accordingly, an object of the present invention is the provision of a new and improved frame lfor a building.

Another object is to provide a frame for a sphericalshaped building having a plurality of structural elements arranged in a substantially semi-spherical pattern of arcs of circles of such pattern and having facilities for maximizing the strength thereof.

Another object is to provide a frame for a building in `which str-ut members are interconnected by joints to form intersecting circles of a sphere, certain of the joints being placed under compression and certain other joints being placed under tension to maximize the strength of the frame.

The term circle Iof a sphere here means a circle, or an arc or portion of a circle, which is -formed by passing a plane through a sphere, whether through the center or obliquely thereto.

With these and other objects in view, a frame for a building, illustrating certain features of the invention, includes a plurality of hollow structural elements of struts arranged in a three-dimensional array of intersectiong circles of a sphere to form a substantially spherical pattern. A plurality of hollow joints interconnect the ends of adjacent struts in each circle of a sphere. A plurality of tensioned stabilizing filamentary members or threads are utilized for maximizing the strength of the frame. One group of stabilizing threads passes through each of the hollow struts and hollow joints of one group of circles of the sphere, and another group of threads is connected externally to another group of joints separated lby at least one other joint in another group of ci-rcles of the sphere.

Other objects and advantages of the invention will become apparent by reference to the following detailed specilication and accompanying drawings, wherein:

FIG. `1 is a schematic plan view of an arrangement of a plurality of struts, the struts forming a frame for a building when erected in a three-dimensional array, incorporating certain principles of the invention;

FIG. 2 is a perspective view of the arrangement of struts shown in FIG. 1 erected in a three-dimensional array and interconnected by joints in the intersecting circles of the sphere of a substantially spherical pattern.

FIG. 3 is a plan view showing one of the joints of FIG. 2 connecting a pair of struts and also showing a stabilizing thread passing through the struts and the joint;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a force diagram of a portion of one circle of a sphere of FIG. 2 showing the forces acting on the joints thereof due to a tensioned stabilizing thread passing through the joints and struts; and

FIG. 6 is a force diagram of a portion of one circle of a sphere of FIG. 2 showing the forces acting on the joints thereof due to a tensioned stabilizing thread connected externally to alternates of the joints.

Referring to FIG. 1, there is schematically shown a plurality of hollow structural elements or struts arranged in a basic pattern of iive identical large squares 11-15 (emphasized by heavy lines) forming across-shaped configuration. Each square is formed with eight interconnected struts of equal length. Struts connecting adjacent ends of the cross-shaped configuration form four identical equilateral triangles 21-24 with the adjacent sides of the squares. Equilat-eral triangles 21-24 do not appear to be equilateral because they are distorted due to viewing them in a plan view. Each large square 11-15 is further subdivided into eight identical right triangles. Only two different strut lengths are required to construct each large square. In large square 14, for example, the struts forming legs 31 of each right triangle are of a irst length and the strut forming the hypotenuse 33 of` a second length.`

Each equilateral triangle 21-24 has a plurality of struts interconnecting each vertex with the midpoint of the opposite leg of the triangle. To construct each equilateral triangle 21-24, two additional strut lengths are required. In equilateral triangle 23, for example, the struts forming the legs 36-38 are of different lengths. However, leg 36 is common to the large squares 11-15 and to equilateral triangles 21-24, and isA equal in length to leg 31.

Therefore, a total of only four different strut lengths, 31, 33, 37, and 38 (note 36 equals 31), are required to construct the basic pattern of tive large squares 11-15 and four equilateral triangles 21-24.

Eight identical rectangles 51-58 are arranged on the ends Vof large squares 11--15` and equilateral triangles 21-24. Rectangles 51-58 are one-half the size of large squares 11-15. Rectangles 55-58 appear to be larger than rectangles `51--54 due to the distortion introduced by viewing the arrangement of struts in a plan view, yet they are equal in size to rectangles 51-54 when the arrangement of str-nts of FIG. 1 is erected into the building frame of FIG. 2.

In FIG. 2, the basic pattern of five large squares 11-15, and four equilateral triangles 21-24 shown in FIG. 1 is assembled or erected to form the substantially semispherical structure shown above the reference or ground line A-A. When the arrangement of struts, shown in FIG. l is erected into the building frame shown in FIG. 2, the struts of the squares 11-15 form eight-sided equilateral polygons and the struts of the equilateral triangles 21-24 form six-sided equilateral polygons. However, for the purpose of facilitating the description of the building frame, each eight-sided equilateral polygon and each sixsided equilateral polygon will still be referred to hereinafter as a square and an equilateral triangle, respectively. The struts of each square and triangle are interconnected by joints which will Ibe described later. The eight rectangles 51-58 are attached to the basic pattern of ve large squares 11-15 and four equilateral triangles 21-24 to form the substantially semi-spherical structure shown above the ground line B-B.

To assist in visualizing the arrangement of five large squares 11-15 and four equilateral triangles 2124 shown in FIG. 2l, certain of these squares and triangles will be identified in FIG. 2. Large square 14 is defined by joints 61-68 in FIG. 2; equilateral triangle 23 -by joints 61, 68, 67, 71, 70 and 69; and large square 13 by joints 67, 72, 73, 74, 75, 76, 70 and 71. Large square 15, and rectangles 54, 57- and 53 are readily recognizable.

Each strut of each square, triangle, and rectangle is connected to another strut by a hollow joint located in a circle of a sphere. For example, in FIG. 2, one circle of a sphere is defined by the reference letters C-C and includes the struts interconnected by the joints 82, 63- 66, center joint 81, 72-75 and 83. Part of another circle of a sphere is defined by reference letters D-D and includes the struts interconnected by the joints 84, 61, 68, 67, and 72. Other circles of a sphere are defined by the ground lines A-A and B-B. It will be understood that each strut is a part of a circle of a sphere and that the circles of a sphere are not true circles but are close approximations thereof.

A hollow joint is located in the center of each large square 11-15 and each equilateral triangle 21-24. For example, in FIG. 2, center joints 81, 85, 86, and 87 are located in the centers of large squares 15, 14, 13, and equilateral triangle 23, respectively.

In FIGS. 3 and 4, a pair of opposed hollow struts 88 and 89 have spherical end portions 91 secured to or formed on both ends thereof. Likewise, all the other struts of the frame are hollow and have spherical end portions 91 formed on both ends thereof.

Each of the joints, for example center joint 81, is hollow and has an upper half member 92 which is identical to a lower half member 93. Each half member 92 and 93 has a plurality of opposed pairs of hemispherical recesses 94 and 95 formed in its periphery. A bolt 98 extends through both half members 92 and 93 of the joint for locking the halves together. The hollow interior or channel 96 of the joint interconnects the hollow passageways of the struts. Bolt 98 has an eye ring 99 formed on the end thereof. The hemispherical recesses 94 and 95 of the upper and lower half members 92 and 93 are aligned when the half members are lock-ed together and form spherical sockets which receive the spherical end portions 91 of the struts. The spherical ends 91 of the struts are thus enabled to swivel within the spherical sockets when the frame is erected.

Each joint depicted in FIGS. 3 and 4 can have the end portions 91 of up to eight struts received in the spherical sockets formed in the periphery of the joint, for example center joint 85 accommodates eight struts, joint 69 accommodates four struts, and so on.

The frame for the spherical-shaped building described above is virtually self-locking and will not come apart except upon a substantially uniform expansion of -all of its parts. A frame constructed in this manner is inherently strong. However, in order to maximize the strength and to prevent the collapse of the frame due to expansion of its parts, a plurality of stabilizing filamentary members or threads are utilized. The stabilizing members 101 and 104 are preferably composed of a material having considerable tensile strength, such as steel, nylon or the like. Stabilizing threads used in the frame of this invention are of two kinds, internal and external.

Referring to FIGS. 3 and 4, an internal thread 101 is shown extending through hollow struts 88 and 89 and hollow joint 81. An internal thread 101 extends through each hollow strut and each hollow joint of each circle of a sphere of the frame. For example, in FIG. 2 the internal thread 101 is anchored to the joint 82 and extends through the hollow struts and hollow joints of the circle of a sphere C-C. A standard tensioning device (schematically shown as 102 in FIGS. 5 and 6) is connected to each internal thread 101 for placing a varying tension thereon.

Referring to FIG. S there is shown a force diagram depicting the forces placed on each joint of a portion of the circle of a sphere C-C due to an internal thread 101. These forces are compressive and their lines of force are directed radially inward toward the center 103 of the frame.

In the structure shown in FIG. 2, an external thread 104 (see FIG. 6) is externally connected to every other joint in each circle of a sphere. For example, in the great circle of a sphere C-C, an external thread 104 is connected to the ring 99 (see FIG. 4) of joints 82, 64, 66, 72, 74, and 83, but not connected to joints 63, 65, 81, 73, and 75 of great circle of a sphere C-C. A standard tensioning device 102 (see FIG. 6) is employed for placing a varying tension on the external threads 104.

Referring to FIG. 6, there is shown a force diagram depicting the forces placed on each joint of a portion of the circle of a sphere C-C due to an external thread 104. The forces on joints 82, 64, and 66 are compressive and their lines of force are directed radially inward toward the center 103 of the frame. The forces on joints 63, 65, and 81 are tensive and their lines of force emanate radially outward from the center 103.

A change in tension on an internal or external thread 101 or 104, respectively, by the manipulation of the tensioning devices 102 effects a change in the compressive and tensive forces on the joints of the associated circle of a sphere. These compressive and tensive forces tend to stabilize and maximize the strength of the frame. Also varying degrees of stabilization and strength are achieved by utilizing stabilizing threads with only certain of the circles of a sphere.

It is optional to use a third stabilizing thread (not shown) with each circle of a sphere. To provide additional strength, a second external thread (not shown) may be connected to those joints not connected by the external thread 104 in FIG. 2; that is, -a second external thread may be connected to joints 63, 65, 81, 73 and 75, and may be anchored to joints 81 and 83 of great circle of a sphere C--C. Thus in FIG. 6, joints 82, 63, 65, and 81 of circle of a sphere C-C would be placed under compression, while joints 64 and 66 would be placed under tension by the second external thread.

In a typical installation, struts having a diameter of inch and nylon stabilizing threads having a diameter of l/s inch have provided a maximum strength frame for a building having a diameter of 20 feet. It is apparent that the diameter of the struts and the diameter of the threads depend upon the diameter of the building.

After the frame is fully assembled, it may be covered with a variety of lightweight materials, for example a lightweight canvas, or a plastic material such as that sold under the trademark Mylan or the like. Alternatively, the covering material may be hung internally from the rings 99 of the bolts 98.

A lightweight frame for a building of the character above-described Whose strength is maximized by stabilizing threads can be effectively employed to suspend a floor from the joints and struts of the frame itself, thus enhancing the portability of the frame.

It is noted that ground lines A--A or B-B are circles of a sphere completely delined by struts of the frame. Such a ground line provides a convenient foundation line and a means of anchoring other circles of a sphere. Therefore, no external anchoring of the circles of a sphere ofthe frame is necessary.

Although the use of stabilizing threads to maximize the strength of the instant frame has been described with respect to a frame comprised essentially of large squares, equilateral triangles and rectangles, it will be apparent to one skilled in this art that the concept of this invention may be applied to -frames for prior art spherical buildings employing other geometric patterns. i

It is to be unedrstood that the above-identified embodiment of a frame for a building is merely illustrative of the principles of the invention and many other embodiments may be devised without departing from the scope of the invention.

What is claimed is:

1. A frame for a building, comprising:

a plurality of hollow struts arranged in a three-dirnensional array of intersecting circles of a sphere to form a substantially spherical pattern,

a plurality of hollow joints interconnecting the ends of the struts in the circles of the sphere, and

a plurality of tensioned stabilizing iilamentary members for strengthening the frame, one group of the members passing through the joints and struts of one group of the circles of the sphere and another group of the members being externally connected to a group of joints separated by at least one other joint in another group of circles of the sphere.

2. A semi-spherical frame for a building, comprising:

a plurality of joints, each joint having a rst half seciton with equally spaced semicircular openings located around the outer periphery thereof and a second superimposed identical half section with the same number and size of semicircular openings positioned around the outer periphery of the second half section to Aform a channel within the half sections and to form a plurality of sockets about the outer periphery of said joint, i

a plurality of hollow struts, each having a partially hollow spherical end portion and being movably mounted within each socket of the joints to interconnect the joints in a substantially semi-spherical pattern of arcs of circles of the semi-spherical pattern with the joints forming the interconnecting junctions of the struts; and

a plurality of stabilizing lamentary members, each having one end thereof connected lto the joint located in the base of the semi-spherical pattern and passing through all the Vhollow struts and joints in the arc of the circle of the spherical pattern wherein the base joint is located and having the other end thereof connected to the other joint in the base of the pattern.

3. A frame -for a building, comprising:

a plurality of hollow joints arranged in a threedimensional array defining points of a substantially spherical pattern, each joint being located with several other joints in circles of a sphere of the spherical pattern,

a plurality of hollow struts, each strut being connected at its ends to two adjacent joints, each joint being connected to an adjacent joint in a circle of a sphere by one strut, and

a plurality of external iilamentary members connected to one group of the joints separated by at least one other joint in one group of the circles of the sphere for strengthening the frame, the external members being placed under tension to exert radially outward forces on the joints not connected by the external member and radially inward forces on the joints connected by the external members.

4. A frame for a building, comprising:

a plurality of hollow joints arranged in a threedimensional array defining points `of a substantially spherical pattern, ea-ch joint being located with several other joints in circles of a sphere of the spherical pattern,

a plurality of hollow struts, each strut being connected at its ends to two adjacent joints,.each joint being connected to an adjacent joint in a circle of a sphere by one strut, and

a plurality of internal filamentary members running through all of the joints and struts of one group of the circles of the sphere for strengthening the frame, the internal members being placed under tension to exert compressive forces on the joints tending to urge the i joints radially inward toward the center of the spherical pattern.

5. The frame for a building in accordance with claim 4,

and additionally comprising:

a plurality of external lilamentary members connected externally to one group of the joints separated by at leas-t one other joint in one group of the circles of the sphere for strengthening the frame, the external -members being placed under tension to exert tensive forces on the joints not connected. by the external members tending to urge these joints radially out- Ward from the center of the spherical pattern.

6. A frame for a building, comprising:

a iirst group of struts being arranged in a substantially semi-spherical array of ve eight-sided equilateral polygon units forming a cross-shaped conguration;

a second group of struts connecting adjacent ends of the cross-shaped configuration forming six-sided equilateral polygon units with the adjacent sides of the eight-sided polygon units between said ends;

a plurality of joints interconnecting the adjacent ends of the rst and second groups of struts;

a center joint located in the center of each of the eightsided and six-sided polygon units; and

a third group of struts connecting each center joint to the surrounding joints in each respective polygon unit.

7. A -frame in accordance with claim 6, wherein each strut and each joint is hollow and is part of a circle of a sphere of a substantially semi-spherical pattern, and additionally comprising:

a plurality of tensioned stabilizing lamentary members for strengthening the frame, one group of the members passing through the joints and struts of one group of the circles of the sphere and another group of the members being externally connected to alternating joints in another group of the circles of a sphere.

8. A frame in accordance with claim 6, wherein each strut and each joint is hollow and is part of a circle of a sphere of a substantially semi-spherical pattern, and additionally comprising:

a plurality of external filamentary members connected to one group of the joints separated by at least one other joint in one group of the circles of the sphere for strengthening the frame, the external members being placed under tension to exert radially outward forces on the joints not connected by the external members and radially inward forces on the joints connected by the external members.

9. A trarne in accordance with claim 6, wherein each strut and each joint is hollow and is part of a circle of a sphere of a substantially semi-spherical pattern, and additionally comprising:

a plurality of internal lamentary members running through all of the joints and struts of one group of the circles of the sphere for strengthening the frame, the internal members being placed under tension t0 exert compressive forces on the joints tending to urge the joints radially inward toward the center of the spherical pattern.

10. A frame in accordance With claim 9, and additionally comprising:

a plurality of external lamentary members connected externally to alternates of the joints in one group of the circles of the sphere for strengthening the trame, the external members being placed under tension to exert tensive forces on the joints not connected by the external member tending to urge these joints radially outward from the center of the spherical pattern.

References Cited UNITED STATES PATENTS FRANK L. ABBOTT, Primary Examiner.

10 R. S. VERMUT, Assistant Examiner. 

6. A FRAME FOR BUILDING, COMPRISING: A FIRST GROUP OF STRUTS BEING ARRANGED IN A SUBSTANTIALLY SEMI-SPHERICAL ARRAY OF FIVE EIGHT-SIDED EQUILATERAL POLYGON UNITS FORMING A CROSS-SHAPED CONFIGURATION; A SECOND GROUP OF STRUTS CONNECTING ADJACENT ENDS OF THE CROSS-SHAPED CONFIGURATION FORMING SIX-SIDED EQUILATERAL POLYGON UNITS WITH THE ADJACENT SIDES OF THE EIGHT-SIDED POLYGON UNITS BETWEEN SAID ENDS; A PLURALITY OF JOINTS INTERCONNECTING THE ADJACENT ENDS OF THE FIRST AND SECOND GROUPS OF STRUTS; A CENTER JOINT LOCATED IN THE CENTER OF EACH OF THE EIGHTSIDED AND SIX-SIDED POLYGON UNITS; AND 